Metal plating is widely performed in order to impart metallic luster to surfaces of substrates and to enhance corrosion resistance and rust prevention.
However, it is known that, for example, the fatigue strength of a member subjected to usual chrome plating is lower than the fatigue strength of the member before being subjected to plating. This is considered to be caused by tensile residual stress and microcracks occurring in the chrome plating layer formed on the surface of the member. Furthermore, if microcracks reach the underlying member, corrosion resistance will be degraded.
In order to overcome such a problem, for example, Non Patent Literature 1 reports that by forming a chrome plating layer having high compressive residual stress and having no microcracks on the surface of a substrate by controlling pulse conditions in pulse electrolysis, the fatigue strength of the substrate may be increased by 30%.